Memory cell density, such as that of non-volatile memory, has been improved significantly in an effort to achieve greater storage capacity, while not significantly increasing cost or memory footprint. One widely adopted solution has been to implement memory cells in three-dimensions, for instance, using vertically oriented NAND strings.
Implementing memories in this manner has presented challenges, however. For example, as a result of three-dimensional implementation, implementing buffers used in program operations with sufficient capacity has proven problematic.